Question

Choose the correct statement(s) about High Earth Orbit (HEO) missions:

1. These orbits are higher than 35,786 km.

2. Mangalyaan and Chandrayaan missions used such orbits.

3. HEO is a subtype of LEO.

• A. 1 & 2 only
• B. 2 & 3 only
• C. 1 only
• D. All are correct

Answer 1

Answer:

A. 1 & 2 only

• Correct Answer: Option A (1 & 2 only)

• High Earth Orbit (HEO) Explanation:

• Statement 1 is CORRECT: High Earth Orbits are defined as orbits with an altitude higher than 35,786 km from Earth's surface. This altitude corresponds to geostationary orbit (GEO), and any orbit beyond this is classified as HEO.

• Statement 2 is CORRECT: Both Mangalyaan (Mars Orbiter Mission) and Chandrayaan missions utilized high earth orbits during their transfer trajectories to their respective destinations. These missions used highly elliptical Earth orbits with apogees (highest points) beyond 35,786 km as part of their trans-Mars or trans-lunar injection phases.

• Statement 3 is INCORRECT: HEO is not a subtype of LEO (Low Earth Orbit). These are distinct orbit classifications:

• LEO: Orbits between approximately 160 km to 2,000 km

• MEO (Medium Earth Orbit): Orbits between 2,000 km to 35,786 km

• GEO (Geostationary Earth Orbit): Orbits at 35,786 km

• HEO: Orbits beyond 35,786 km